Distribution of 4FGL-DR4 sources in feature space. In each panel, we show the distribution of pulsars (blue), blazars (red), and unassociated sources (black) in different parameters. The left panel compares the observed energy flux F_γ in the 100 MeV – 100 GeV band to its estimated error σ_γ. The central panel compares the significance of detection with that of spectral curvature for a log-parabola model. In the right panel, this is compared with the measure of variability on monthly to yearly scales. In each panel, the dashed gray line indicates the direction perpendicular to which we defined our composite parameters to be able to better separate the source types.